A geologist prepares a solution from a rock sample and analyses it using flame emission spectroscopy. The reference wavelengths and the wavelengths recorded for the rock solution are shown in the table.
| Metal ion | Wavelengths of main lines in nm |
|---|---|
| Lithium | 610 and 671 |
| Sodium | 589 and 819 |
| Potassium | 404 and 766 |
| Calcium | 423 and 622 |
| Rock solution | 404, 610, 671 and 766 |
The solution contains two of the metal ions listed. Name these metal ions.
93 exam-style questions on AQA GCSE Chemistry 8.3 Identification of ions by chemical and spectroscopic means, covering 8.3.1 Flame tests, 8.3.2 Metal hydroxides, 8.3.3 Carbonates, 8.3.4 Halides, 8.3.5 Sulfates, 8.3.6 Instrumental methods, and 8.3.7 Flame emission spectroscopy. Each one has a worked solution and a mark scheme showing where the marks go.